In certain implantable prostheses, artificial urinary sphincters and artificial anal sphincters consisted of at least one inflatable cuff surrounding at least a portion of the urethra or anal canal and the cuff is inflated to provide continence or deflated to void, at least one fluid reservoir and a fluid transfer system consisting of at least one pump bulb and at least one valve. The fluid transfer system transfers fluid from the reservoir to inflate the cuff and returns fluid to the reservoir when the cuff is deflated.